Photoluminescence imaging and micro-crack detection are important inspection procedures in semiconductor wafer processing. Transmitted or reflected images of a semiconductor wafer are taken with line scan image cameras and analyzed for, among other things, micro-cracks and photoluminescence features.
One of the challenges facing the solar industry is to lower the cost of manufacturing solar cells. Current systems utilize a single illuminator and camera for each image to be taken during the inspection process. Cameras useful for current semiconductor inspection processes are expensive; cost of inspection becomes a significant factor of manufacturing when multiple cameras are needed to collect multiple images to evaluate various proprieties of samples. In addition, a failure of any one camera in an inspection system may compromise the entire process; therefore reliability may suffer with each additional camera in the system.
Consequently, it would be advantageous if an apparatus existed that is suitable for imaging semiconductor wafers illuminated by multiple wavelengths and at multiple angles with a single camera, and minimize the number of cameras needed to acquire multiple properties of the samples.